Alfalfa hay is a major crop for the feeding of livestock. The most prevalent method of harvesting and handling alfalfa hay, is to cut the hay, lay it in windrows and let the natural elements (sun and wind) dry the hay in the windrow down to a level of moisture that is acceptable for baling. The moisture level that is acceptable for baling is set on the high end at 18% moisture due to the occurrence of mold growth that can significantly reduce the feed quality of hay harvested above that level. The low end limit is 14% moisture. Around one-half of the nutrients in alfalfa hay are in the leaves. Due to the thin structure of the leaves, below 14% moisture, they will become brittle and shatter as the windrow is mechanically handled by the hay baler. Operating within this narrow band, 18% moisture on the high side and 14% moisture on the low side, imposes significant limitations to operating time for balers of alfalfa hay.
A common practice for baling hay in the drier regions of production, is to bale at night. The alfalfa is cut and windrowed, and the windrows are allowed to dry completely, usually down to around 10% taking normally three to six days. This allows for the producer to know that all the hay in the windrow is below 18% and no spoilage will occur. Then to prevent excess leaf loss, the operator waits for the condensation of dew to occur, usually at night. As the dew evenly condenses on the warmer hay as the air temperature drops, the windrow is evenly brought up in moisture above the lower limit for acceptable baling. If the dew becomes too heavy and brings the windrow moisture up above the upper limit (18%) production must be suspended until the moisture again begins to dry off the hay. Using this technique for baling, although acceptable, is limited by the hours when the right amount of dew is in the windrow.
Producers of alfalfa have tried simulating the way that dew adds moisture to hay, but have to date, had limited success. Spraying water over the top of the windrow has added moisture only to the top surface of the windrow while the rest of the hay remains too dry for baling. Attempts to mechanically move the windrow so that water can be added to the lower surfaces have also proven unsuccessful in that any mechanical handling of a dry windrow shatters the leaves off. The device that has been invented allows for moisture to be added evenly throughout the windrow without moving the windrow.